Boeing and the FAA have been extremely secretive about what their solution to the MCAS problem will be. All that Boeing has said was that they would have a software fix that would do four things:
First, they will increase the number of sensors from only using one sensor to using two sensors. This change will do nothing about the real problem – the instability problem - created when Boeing moved the new engines forward and up.
Second, the software fix will reduce the power of MCAS to push the nose of the plane down. This change will also do nothing about the real problem – the instability problem - created by moving the new engines forward and up.
Third, the software fix will eliminate the infinite loop problem of MCAS reactivating itself repeatedly. This change will also do nothing about the real problem – the instability problem - created by moving the new engines forward and up.
Fourth, Boeing will do a better job of explaining to pilots how they can turn MCAS off. This change will also do nothing about the real problem – the instability problem - created by moving the new engines forward and up.
Problem Solving 101 – Identify the Underlying Cause of the Problem
In order to solve any problem, it is important to focus on the underlying cause of the problem. The underlying problem of the Boeing 737 Max is that moving the large and powerful new engines too far forward in front of the wings and too high up in front of the wings caused the 737 Max to have an extreme tendency to have the nose of the plane tip up too high. This extreme nose up position is just as dangerous as an extreme nose down position because extreme nose up can lead to a stall and loss of control of the airplane just as extreme nose down can lead to a dive and loss of control of the airplane.
The reason stalling an airplane as large as a 737 Max is dangerous is that there are huge forces involved. There are also Positive Feedback Loops involved. This means that once the nose of any airplane (not just the 737 Max) gets too high (near a stall angle), the nose will start to rise even faster making the stall much worse and lead to a very rapid loss of control of the airplane. Bigger faster planes present exponentially greater surface areas making stall recovery much more difficult. The whole point of a stable airplane design is that the plane should be aerodynamically stable. The plane should be naturally balanced around its center of gravity and should not require a highly experienced pilot in order to avoid stalling.
Designing commercial airplanes to be aerodynamically stable is not merely a good idea. It is a federal law. Here is the stall regulation that Boeing violated when they moved the engines of the 737 Max too far forward and too far up:
14 CFR §25.203 Stall characteristics.
(a) It must be possible to produce and to correct roll and yaw by unreversed use of the aileron and rudder controls, up to the time the airplane is stalled. No abnormal nose-up pitching may occur. The longitudinal control force must be positive up to and throughout the stall. In addition, it must be possible to promptly prevent stalling and to recover from a stall by normal use of controls.
(b) For level wing stalls, the roll occurring between the stall and the completion of the recovery may not exceed approximately 20 degrees.
Title 14 is the section on FAA Airplane Standards. Part 25 is the Airworthiness Standards for commercial planes. Section 203 is the law intended to prevent and recover from stalls. The stall prevention and recovery test – a test that must be conducted on any new plane – and therefore must have been conducted on the 737 Max in 2016 – is described in this document: https://www.govinfo.gov/content/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec25-203.pdf
Moreover because MCAS is also an automatic power operated stability augmentation system, it is also subject to these two federal laws which Boeing also broke:
14 CFR §25.671 General Control System Requirements
(c) The airplane must be shown by analysis, tests, or both, to be capable of continued safe flight and landing after any of the following failures in the flight control system and surfaces (including trim, lift, drag, and feel systems), within the normal flight envelope, without requiring exceptional piloting skill or strength.
14 CFR §25.672 Stability augmentation and automatic and power operated systems
If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show compliance with the flight characteristics requirements of this part, such systems must comply with §25.671 and the following:
(a) A warning which is clearly distinguishable to the pilot under expected flight conditions without requiring his attention must be provided for any failure in the stability augmentation system or in any other automatic or power-operated system which could result in an unsafe condition if the pilot were not aware of the failure. Warning systems must not activate the control systems.
(b) The design of the stability augmentation system or of any other automatic or power-operated system must permit initial counteraction of failures of the type specified in §25.671(c) without requiring exceptional pilot skill or strength, by either the deactivation of the system, or a failed portion thereof, or by overriding the failure by movement of the flight controls in the normal sense. https://ecfr.io/Title-14/pt14.1.25#se14.1.25_1672
Put in plain English, federal law prohibits Boeing from producing a plane with an extreme nose up tendency. Federal law also prohibits Boeing from producing an Augmentation System which cannot be counter acted by a normal pilot. Boeing was well aware of both laws – which is why the true power of MCAS had to be hidden from the FAA. The MCAS system was so well hidden from the FAA that a 30 page report by the FAA listing all of the new features of the 737 Max did not include a single reference to MCAS (see pages 64 to 94, Model 737-8 approved on March 8 2017). Page 88 states: “Modifications that reduce flight critical system separation or adversely impact survivability of systems are not acceptable.”
http://www.b737.org.uk/a16we.pdf
The design of the Boeing 737 Max clearly violates several federal laws. In the next section, we will take a closer look at how these crimes occurred.